In such a connector, usually, a shield cover is contacted with a case of an apparatus in a plug insertion port to establish a grounding connection, thereby enhancing the shielding performance. For example, Patent Literatures 1 to 6 listed below disclose a connector in which, in addition to mounting terminals for a printed circuit board and a contact piece for a shield member of a plug, a contact piece for a case is disposed in a plug insertion port of a shield cover.    [Patent Literature 1] Japanese Patent Application Laying-Open No. 10-64636    [Patent Literature 2] Japanese Patent Application Laying-Open No. 11-67365    [Patent Literature 3] Published Japanese Translation of PCT Patent Application No. 2000-515302    [Patent Literature 4] Japanese Utility Model Registration No. 3,056,506    [Patent Literature 5] Japanese Patent No. 3,098,520    [Patent Literature 6] Japanese Patent Application Laying-Open No. 2008-103271
In a so-called EMI shielded connector, as in a connector in which no countermeasure is taken, cost reduction and miniaturization are strongly requested, and a high shielding performance must be realized while satisfying these requests.
In the connectors disclosed in, for example, Patent Literatures 4 to 6, a contact piece for a case is disposed as a separate member in a shield cover, and hence the number of components is increased. Consequently, there arises a problem in that the assembling manpower is correspondingly increased and the production cost is raised.
By contrast, the connectors disclosed in, for example, Patent Literatures 1 to 3 include a shield cover in which mounting terminals for a printed circuit board, a contact piece for a shield member of a plug, and a contact piece for a case are integrally disposed by applying punching and bending processes on one metal plate. The production cost can be suppressed as compared with the connectors disclosed in, for example, Patent Literatures 4 to 6.
In the case of the connector disclosed in, for example, Patent Literature 2, however, a simple outward-directed flange which is disposed in the opening edge of a plug insertion port is used as a contact piece for a case. In the case where the connector is pryed when the plug is inserted, for example, there is a possibility that the contact piece may be separated from the case to disconnect the grounding connection (see Paragraphs 0002 to 0011 and the like of Patent Literature 1). Furthermore, there is a problem in that the outer shape of the connector becomes large. In the case where the contact piece (outward-directed flange) is screwingly fastened to the case (see the flange portion 56 and the like of Patent Literature 6), the outer shape of the contact piece must be further enlarged. Therefore, the outer shape of the connector is further enlarged, and the number of components is increased. Consequently, the assembling manpower is correspondingly increased and the production cost is raised.
By contrast, in the case of the connectors disclosed in, for example, Patent Literatures 1 and 3, an elastic piece in which the tip end is pressingly contacted with the case is used as a contact piece for the case. Even in the case where the connector is pryed when the plug is inserted, for example, the contact piece can maintain the contact state with the case because of the elasticity of the contact piece. Therefore, the reliability of the shielding performance is more easily ensured as compared with the case of, for example, the connector disclosed in Patent Literature 2.
In the case of the connector disclosed in, for example, Patent Literature 1, however, an elastic piece which is partly cut and raised from the outward-directed flange disposed in the opening edge of the plug insertion port is used as a contact piece for the case. Similarly with the case of the connector disclosed in, for example, Patent Literature 2, there is a problem in that the outer shape of the connector becomes large. On the other hand, in the case of the connector disclosed in, for example, Patent Literature 3, the plurality (upper and lower two stages) of plug insertion ports are formed by one shield cover. An elastic piece is inward extended from the opening edge which is between the upper and lower plug insertion ports, and used as the contact piece for the case, so that the contact piece does not interfere with the inserted plug. There is no problem in that, as in the case of the connector disclosed in, for example, Patent Literature 1, the outer shape of the connector becomes large. However, the configuration cannot be employed in a connector in which only one plug insertion port is formed by one shield cover as in, for example, the connector disclosed in Patent Literature 1. In a connector in which only one plug insertion port is formed by one shield cover, therefore, only a contact piece which is outward extended from the opening edge of the plug insertion port can be disposed (a contact piece which is inward extended interferes with an inserted plug), and hence there is a problem in that the outer shape of the connector is inevitably large.
In the case of the connector disclosed in, for example, Patent Literature 3, an elastic piece which is inward extended from the opening edge of a plug insertion port while being bent with forming a small gap with respect to a case that is immediately in front thereof is formed as a contact piece for the case. Therefore, the bend radius of the contact piece from the opening edge of the plug insertion port cannot be set to be large, the contact piece is restricted to have a short length, and a large stress is produced in the contact piece, thereby causing problems in that breakage or plastic deformation easily occurs, and that adequate elasticity is hardly obtained. When the gap between the opening edge of the plug insertion port and the case is enlarged, the shielding performance is reduced.
In a conventional connector which is so-called EMI shielded connector, as described above, it is difficult to realize a highly reliable shielding performance while reducing the production cost and the size.
The invention has been conducted in view of above-discussed circumstances. It is an object of the invention to provide a connector in which a highly reliable shielding performance can be realized while reducing the production cost and the size.